Pressurized gas burner



Dec. 22, 1964 G, H, BROWN ETAL 3,162,237

PRESSURIZED GAS BURNER Filed Oct. 2. 1961 United States Patent 3,l62,237 Patented Dec. 22, 1964 vttiee 3,162,237 PRESSUREZED 'GAS BURNER lGordon H. Brown and Creston l. Bruce, St. lloseph,

Mich., assigner-s to Whirlpool Corporation, a corporation of Delaware Filed (ict. 2, 196i, Ser. No. 142,285 12 Claims. (Cl. 158-99) This invention relates to a new design for a gas burner for use on a domestic gas range or cooking stove.

The design of the burner is directed to features that overcome some of the undesirable features inherent in many of the present-day range gas surface burners of the atmospheric type.

Present atmospheric gas surface burners require large amounts of secondary air to effect efficient as well as safe combustion. This large secondary air requirement maires it essential that the burner combustion area be above the range so that secondary air is readily available. However, when a utensil or pan is set on the burner grates, the space between the periphery of the plan and the range top sometimes is restricted to the extent that enough secondary air can not pass through this space to the combutsion area directly below the pan to assure efficient and safe combusion under all conditions. Therefore, it is customary in domestic gas range design to provide a clearance between the gas burner and the range top as an additional source of secondary air from below the range top to assure efiicient and safe combustion under all conditions. This second necessary space for secondary air ilow is very undesirable when the inevitable spillage or boiling over from the cooking pan takes place since the spillage may tlow through this space and onto the burner gas supply lines and controls below the range top creating a very diliicult cleaning problem. This spillage can also plug some of the burner gas outlet ports.

In addition to the psychological disadvantages of an exposed open flame above the range top there are also other important disadvantages. Naturally, if care is not taken, it is possible to ignite articles of clothing and items such as hot pads when moving pans about on the range top. Also, the necessity of having the combustion area above the range top to assure the required quantity of atmospheric secondary air allows the burner llame to sometimes directly impinge on the cooking pan causing permanent charring or discoloration of the cooking pans or utensils over and above that caused by the hot gases.

Thus, the gas burner of this invention is designed to eliminate the above explained disadvantages inherent in present-day ranges using atmospheric gas surface burners. Specifically, the gas burner of this invention is designed to provide a combustion area that is completely below the range cook top so that the burner flame is not visible. This in addition to eliminating an exposed llame also eliminates the direct impingement of the llame against the cooking utensils and thus tends to eliminate the permanent damage to the utensils caused by direct flame contact.

Since the combustion area of the burner of this invention is below the range cook top, it is not exposed to the necessary quantities of atmospheric secondary air for eicient and safe combustion. To overcome this deficiency, the entire burner including the primary air intake venturi is enclosed below the cook top in a shell or casing provided with an opening through which the required quantity of secondary air is delivered to the combustion area at an air pressure slightly greater than atmospheric pressure. The combustion area of the burner of this invention is dened by the burner parts adjacent the gas manifold outlet ports, the burner parts adjacent the pressurized secondary air ports and by the utensil support or burner cover. The central open portion of the utensil support extends downwardly through the cook top to a point below the combustion area that surrounds this downwardly extending support portion. A spillage collecting cup or pan is positioned in the burner beneath the central opening in the utensil support. Since an additional'opening is not needed in the cook top to supply secondary air for combustion, all spillage must pass through the central opening in the utensil support and into the spillage collector cup. There is practically no possibility of spillage getting onto the burner parts thus, it is only necessary to remove the utensil support and spillage collector cup in case of spillage.

The slight pressure differential over atmospheric pressure of the incoming secondary air to the combustion area also provides a positive air flow that overcomes the natural air ow due to convection to drive the heat of combustion downwardly out of the combustion area around the bottom of the depressed central portion of the utensil support and upwardly through the central opening to contact and heat the cooking utensil.

The gas burner of this invention is also adapted to be converted to a simple atmospheric burner in case pressurized secondary air is not used. To do this it is only necessary to provide a different utensil support and to remove the spillage cup to allow secondary air at atmospheric pressure to ilow through the area formerly closed by the spillage cup into the combustion area.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein the figure is a diametric vertical section of a gas burner embodying the invention.

In the exemplary embodiment of the invention as disclosed in the drawing, a gas burner generally designated lil is shown to comprise a housing, or box, lll having an upper wall or cook top l2 provided with a central opening i3. Air at a pressure somewhat above atmospheric pressure is delivered to within the housing lll by means of a conventional fan l. driven by conventional means such as an electric motor (not shown). Within the housing lll is mounted an annular insulating support l5 provided with a radially inwardly projecting annular edge portion lo supporting an outwardly turned llange t7 of a sump or spillage pan lil depending downwardly through an opening i9 in the bottom wall 20 of the housing or casing ll. A hollow annular burner ring 21 is supported on the planar upper surface 22 of the support l5 and is provided with a plurality of main outlet ports 23 opening through an upwardly widening frusto-conical surface 24. Combustible gas and primary air is supplied to the annular chamber or manifold 2S within ring 2]. through a duct 26 provided with a venturi portion 2'7 having an inlet Z3 for providing primary air for mixture with the combustible gas in the venturi section prior to delivery through duct 26 to the burner ring. It should be noted that the venturi portion 27 and primary air inlet 23 are positioned within the casing lll and thus primary air enters the inlet 2S at the pressure above that ot the ambient atmosphere around casing lll and created within the casing lll by the blower 14. A main gas line 29 extends through the bottom wall 2li of the casing ll and connects with a modulating type gas ow control valve 29a to control the flow of gas to the outlet ports from the gas inlet line 23a. A pilot gas line is connected to the gas inlet line 28a before the valve 29a and extends upwardly through the bottom wall 2li of the casing 11 so that the pilot line outlet portion 3l is adjacent the main outlet ports 23. This arrangement provides a standing pilot to ignite the gas ilowing through the ports 23 as controlled by the valve 29a. if desired, other ignition means could be used.

Extending upwardly from the upper surface 32 of the burner ring 2l is a frusto-conical, upwardly narrowing wall member 33 provided with a vplurality of circumferentially spaced secondary air apertures V3A. NallV lmember 33 and burner ring 21m-operatively define an outer boundary of a combustion chamber 35 wherein the gas delivered through ports 23 is burned, the 'commaybe made without departing from the spirit and scope bustion being supported by thev primary air delivered through opening 28 to the venturi section 27, and secondary air delivered t the combustion chamberl 35 through apertures 34.

The linner boundaryY of combustion chamber defined bya radially inner, downturned portion 36 of a ceramic coverfor utensil support 37,'extending downwardly radially inwardly of the insulating support 15.-

Thus, combustion chamber 35 comprises a downwardly opening annular chamber wherein the flames 38 produced by the burning combustible gas are effectively covered so that no live dame isexposed upwardly. The

of the invention as defined in the appended claims.

We claim:

Y 1. r*.rburner comprisin'g means defining ,a combustion chamber; means providing combustible gas and 'primary air at aV positive pressure to said'chamber; Vmeansvproviding secondary air at a positive pressure to said chamhot products of combustion, however, pass downwardly f because of the pressure of theV secondary-air--produced by the blower 14 from the combustion chamber 35 'andy thenupwardly through the'central circular opening 39 defined by cover portion 36 to heat a superposed element tol be heated, such as a cooking utensil E. This pressurized air assures proper combustion, heat transfer, and air iow contra to that normally'produced in natural convection.l

A downwardly directed flange lilla of cover 37 is supported in resting engagement on the upper Vwall portion 12 of the housing 1l to support the cover 37 T he cover ily removable..Y

berv for supporting combustion of said gas to provide a ame therein; cover means Viullyjoverlying said chamber for effectively fully precluding upward exposure of'Y theliame'in'normal'operation of the burner, said cover means defining a passage for passing hot vproducts Vof Vcombustion upwardly ,to heat a superposed element; and `insulating means for directing the products of combustion 4.4 The burner of.claim 1 wherein said combustion chamberopens downwardly. v

is provided with a rightcylindrical surface 41 Vengaging 'v a wall member flange 4@ of wall member 33 to retain the cover coaxially in the burner.. As show-inthe inner surface 42 of the cover preferably flares outwardly thereby facilitating the delivery of thehot products vofvc'ombustion upwardly fromthe burner and providing a wide l uniform distribution thereof effectively precludingrthe formation of hot spots on Vthe bottom of utensil E. To

facilitate lthe liow of thehot products of combustion' un-v l der substantially the entire bottom surface 43 of the utensil, circumferentially spaced,'radially extending supf Y port ribs 44 are molded integrally with the cover 37 to provide radial passages for thev hot gases against Vthe bottom 43 of the utensil E. It is also possible to make the coverV 37 and ribs as separate parts. The cover and ribs have to be designed to provide a dispersed air flow at a controlled ,velocity of flow.

Thus, burner 10 provides an improved convective heatn ing of the utensil or element to be heated. Upward exposure of the fiame is effectively precluded, the heating of the utensil being 'effected by the hot products ofV combustion passing upwardly from the burner in a uniform even distribution against the utensil. VAir for supporting combustion of the combustible gas in theV combus- Y tion chamber is provided thereto at a positive pressure, y assuring the necessary quantity of secondary air for high eficiency and safe operation. The 'cover 37 and sump pan 18 are readily removable for facilitated cleaning.,

Further, as the combustion chamber is effectively covered by the cover 37, spillage is directedaway from the burner Vports thereby veffectively assuring. a simple cleaning job in case of spillage land alsoy practically eliminatingfthe possibility of the burner beingc'ompletely extinguished l with the valve 29a remaining open.

Still another desirable feature of the burner 10 is thev arrangement thereof for ready use as a generally conventional .exposed ame atmospheric burner utilizing ambient, non-pressurized air as, for example during .a power 5. Aburner comprising: means defining an annular combustioncham'ber; l means providing combustible gas and primary combustion-supporting air to said chamber to provide a flame therein; cover means overlying said chamberl for effectively fully precluding upward ex-.

posure of the fiame in'normal operation of the burner, said cover means dening an' axial passage for passing hot products of combustion upwardly from said chamber to heat a superposed element; and sump means coaxially subjacent said axial passage for'collecting spillage and the like. i

' 6. A burner comprising: means defining an annular Vcombustion, chamber; means providing combustible gas Vand primary combustion-supporting air-to said chamber to provideY a flame therein; means providing secondary air to said chamber for additionally supporting combustion of said/combustible gas therein; cover means overlying said chamber for effectively fully precluding upward exposure'of the fiame infnormalv operation of the burner, said .cover means defining an raxial passage for passing hot products of combustion upwardly from said chamber to heat a superposed element; and sump means coaxially subjacent said axial passage for collecting spillageV andthe like. v

7. The burner' of claim 5 wherein said .sump means and said cover meansV are axially upwardly removably carried by said chamber defining means.

V8. The burner of claim-5 wherein said sump means is disposed substantially below the level of said combustion chamber.

9. A burner comprising: wall means defining, a combustion chamber, a first opening in said "wall means for delivering combustible gas and primary air mixture into said chamber to'provide'a'ame therein, a secondopening in saidwall means-for delivering secondary air into said chamber for supporting effectively complete combusf tion of said gas in said chamber, said first land second openings opening yinto said chamber perpendicularly to each other'and said second opening being disposed above said first opening; and cover means fully 'overlying said chamber for, effectively fully precluding upward exposure of the flame'in normal operation oflthe burner, said cover means defining a passagefor passing hot products of combustion upwardlyfrom said chamber to heat a n superposed element. .V V Y K ing to said space; means defining a combustion chamber having an opening to said space, said burner having an opening .to said combustion chamber opening substantiallyperpendicularly and adjacent said chamber opening; means for delivering air under pressure to said space for passing through said opening in the passage means to comprise primary air mixed with the combustible fuel in said passage means and for passing through said opening in said chamber means to comprise secondary air in Said chamber for impinging substantially perpendicularly against a flame emanating from said burner opening and thereby providing improved effectively complete combustion therein; cover means fully overlying said chamber for effectively fully precluding upward exposure of the flame in normal operation of the burner, said cover means defining a passage for passing hot products of combustion upwardly to heat a superposed element; and insulating means for conducting products of combustion from said chamber to exteriorly of the space defining means.

11. A lrange sur-face burner comprising: wall means defining an enclosed cavity and having first and second apertures; Ia hollow, upwardly flared cover member seated in said rst aperture and depending into said cavity; a burner ring positioned within said cavity and encompassing the cover member depending into said cavity; a perforate wall means encompassing the cover member depending into said cavity and cooperating with said cover member and said burner ring to define a combustion chamber therewith; means including a venturi communicating with said burner ring and supplying said burner ring with a combustible air-gas mixture; and Iair translation means positioned adjacent said second aperture for supplying pressurized secondary air to said combustion chamber and to said venturi to promote complete combustion of said air-gas mixture within said combustion chamber prior to exhaustion of effluent hot gases upwardly through said hollow cover member, said cover member effectively fully precluding upward exposure of the ame in normal operation of the burner.

12. A burner comprising: means defining a combustion chamber; means providing combustible gas and primary air at a positive pressure to said chamber; means providing secondary air at a positive pressure to said chamber for supporting combustion of said gas to provide a iiame therein; and cover means fully overlying said chamber for effectively fully precluding upward exposure `of the ame in normal operation of the burner, said cover means defining a passage for passing hot products of combustion upwardly to heat a superposed element.

References Cited in the le of this patent UNITED STATES PATENTS 569,085 Blanchard Oct. 6, 1896 2,220,572 Knupp Nov. 5, 1940 2,320,754 Sherman June 1, 1943 2,594,562 Jackson Apr. 29, 1952 2,617,404 Prather Nov. 11, 1952 2,675,868 Ray Apr. 20, 1954 FOREIGN PATENTS 370,589 Great Britain Apr. 14, 1932 

12. A BURNER COMPRISING; MEANS DEFINING A COMBUSTION CHABMER; MEANS PROVIDING COMBUSTIBLE GAS AND PRIMARY AIR AT A POSITIVE PRESSURE TO SAID CHAMBER; MEANS PROVIDING SCONDARY AIR AT A POSITIVE PRESSURE TO SAID CHAMBER FOR SUPPORTING COMBUSTION OF SAID GAS TO PROVIDE A FLAME THEREIN; AND COVER MEANS FULLY OVERLYING SAID CHAMBER FOR EFFECTIVELY FULLY PRECLUDING UPWARD EXPOSURE OF THE FLAME IN NORMAL OPERATION OF THE BURNER, SAID COVER MEAND DEFINING A PASSAGE FOR PASSING HOT PRODUCTS OF COMBUSTION UPWARDLY TO HEAT A SUPERPOSED ELEMENT. 